Real-Time Adaptive Selective Harmonic Elimination for Cascaded Full-Bridge Multilevel Inverter

Abstract

Selective Harmonics Elimination is a high-efficiency modulation method for multilevel inverters that allows handling very high voltage applications. It eliminates the most significant harmonics and fixes the desired fundamental component. The main issue of these techniques is the complex process to obtain the appropriate switching-angles, being necessary to calculate them offline, meaning that if some disturbances occur, the system will not be compensated. This article proposes a real-time selective harmonic elimination for a single-phase cascaded multilevel inverter. The control strategy maintains constant the fundamental component of the output voltage while removing its third, fifth, and seventh order harmonics. The switching-angles are dynamically adapted to compensate for variations in the input voltage and the load. This is done by obtaining a virtual dynamic system using Groebner basis, an adaptation of the Newton-Raphson method, and implementing a digital PI controller into the virtual dynamical model. This adaptive modulation technique is validated experimentally in a 200 W, 9-levels Cascaded Full Bridge Inverter, canceling the harmonics and regulating the fundamental components in all the tests. The developed theory can be adapted or extended for any multilevel inverter modulated by selective harmonic elimination.

Harmonics and Interharmonics Detection Based on Synchrosqueezing Adaptive S-Transform

“…Although ST inherits the advantages of STFT and WT, the fixed trend of σ varying with the frequency deteriorates the time-frequency resolution of ST, according to (3). Therefore, an AST algorithm is built to afford the TFS of the harmonic signal.…”

“…With a high proportion of new energy generation and nonlinear power electronics connected to the grid, the impact of harmonics and interharmonics on power quality is of increasing concern [1]. Harmonics represent grave hazards, such as motor noise, voltage deviation and resonance for transformers, motors, arc furnaces, metering instruments and other industrial equipment [2][3][4]. Moreover, harmonics can also result in grid-voltage fluctuations as well as the flicker, resonance, and over-zero shifts in the voltage waveform [5,6].…”

Decentralized Control for the Cell Power Balancing of a Cascaded Full-Bridge Multilevel Converter

“…Depending on the connection of these cells (series or parallel), the current or voltage is divided. Within the family of multicellular converters, one can mention the following, among others: the Flying Capacitor Multilevel Converter (FCMC) [3][4][5][6][7], CFBMC [8][9][10][11][12][13] and the Multiphase Buck Converter [14][15][16]. They distribute, respectively, the input voltage, the output voltage and the output current.…”

A novel adaptive invasive weed optimization technique and least square regression for harmonics minimization in standalone PV applications

“…A comparative analysis of numerous intelligent optimization techniques to minimize the specific harmonics in the output waveform is given in Memon et al 27 The implementation of computed switching angles for real-time implementation has been proposed in literature. 56,57 Neural network-based selective harmonic elimination has been proposed in Toubal Maamar et al 58 A generalized low switching frequency modulation technique for converters has been proposed in Wu et al 59 Real-time adaptive selective harmonic elimination for multilevel converter has been proposed in Vivert et al, 60 and generalized real-time selective harmonic elimination/modulation is proposed in Janabi et al 61 Selective harmonic elimination model predictive control for multilevel power converters has been proposed in Aguilera et al 62 In this paper, a standalone system with battery storage and three-phase inverter has been proposed. A novel adaptive invasive weed optimization (AIWO)-based intelligent technique has been proposed to calculate the switching angles in bipolar voltage waveform of a two-level VSI.…”